Been going so well I've not posted much about this. For a while I have noticed the silencer slip coupling is wearing thin on the exhaust. Tried several things but the pipe is just too old and probably 20,000 miles. Needs welding repair and a major de-coke.
Exhaust is a JL RZ mark I right hand, this is not ideally suited to this engine as it doesn't really have the expansion capacity for this MHR. They were never designed for much more than 20bhp 15 years ago.

Been going so well I've not posted much about this. For a while I have noticed the silencer slip coupling is wearing thin on the exhaust. Tried several things but the pipe is just too old and probably 20,000 miles. Needs welding repair and a major de-coke.
Exhaust is a JL RZ mark I right hand, this is not ideally suited to this engine as it doesn't really have the expansion capacity for this MHR. They were never designed for much more than 20bhp 15 years ago.

No dyno charts or even opinion on pipes... except to mention that JL pipes can be bought directly. Good (better) prices and excellent company to deal with. Oliver Lomas went out of his way to help me...

That MRP plate sure opens up a few possibilities. I wouldn't know where to start looking for stuff like that. Definitely time for a fatter pipe and even the JL RZ interfered with the stand, so going to be an issue.

Know any more right hand exhausts? Pipe design don't seem to make any. And JL only make the one I have. Surprised the JL site doesn't have the SIP Performace 2.0 on it as JL are supposed to make it.

That MRP plate sure opens up a few possibilities. I wouldn't know where to start looking for stuff like that. Definitely time for a fatter pipe and even the JL RZ interfered with the stand, so going to be an issue.

Know any more right hand exhausts? Pipe design don't seem to make any. And JL only make the one I have. Surprised the JL site doesn't have the SIP Performace 2.0 on it as JL are supposed to make it.

Try contacting them. Maybe you can still get it direct. I ordered direct as both SIP and SC were out of stock. Turned out well for me.

I had an old Scoot RS pipe on mine, which was left hander. I actually found it easier to change the rear wheel than any other pipe. First thing I did was slot the rear part of the bracket off the swing arm (something I do to every pipe I get my hands on).
When you need to change the tyre you tip the scooter over and unscrew the bolt on the bracket until it's just free of the captive nut. Next you simply swing the pipe down out of the way, pivoting at the connection just after the downpipe. Easy peasy.

BTW, it allows a spare wheel, works fine with the stand (needs the smaller double spring setup though) and drops in 2 minutes. With the tubeless rims, even before the Cobra, I never had to take out the wheel unless it was for something major (brake shoes, clutch plates, etc.). Oh, and so far, I never had a flat. Yes, I agree the clutch cable is a bit of a PITA (but even with a right hand exhaust it will be the same) but I am using Michael's method and so far it's been pretty easy...

Set the jetting to hold the temperature down to about 280/300F at all points. This is rich but proves I have control of the temperature.
Now the fun begins.
Last few days I have been weakening the jetting to allow 320F at WOT. Together with adjusting the timing and Kytronic.

60 & B60 pilot, DQ262 atomiser, K93 needle @1.5 clip, 165 main jet

Seems to be settling down nicely. Will continue fiddling with the settings but very close now.

I did several videos but the wrong kind of sun is making too much glare for the speedo. Had to do 5 runs to get this one but I'm not complaining. This wasn't the quickest but the only one where the speedo can be read. Really is some scooter now. Great to ride.

Thanks for posting this!

Just want to double check, which carb did you use?

And a question after watching the video, when you roll off the throttle it seems to be smooth, the noise.

Iím getting a lot of machine gun noise when I come off the throttle, any ideas why?

Jack, just came across the following in one of your Scooterotica posts:

"btw, Mine has a JL RZ rhs on too and have no plans to change it, ever!"

Jokes aside, I was using the thread to give me some more pointers for my MHR build. All good stuff.

Had to go and check, that post was 2014 Exhaust wasn't new then but had been on maybe a year at that point. Different crank, cylinder, head, flywheel now. With the old 210 it was great but on the MHR its out the game before the full rpm. Could be losing as much as 5bhp from the top.
All the new pipes I want are going to be months away. Out of stock or made to order. The old RZ will need a patch up to get through the Summer.

108 wrote:

Thanks for posting this!

Just want to double check, which carb did you use?

And a question after watching the video, when you roll off the throttle it seems to be smooth, the noise.

Iím getting a lot of machine gun noise when I come off the throttle, any ideas why?

Carb is Race polished Dellorto VHSH30CS. Although this one punches above its weight, it is a little small and all it's expensive parts are getting worn out. A whole new one would make more sense.

Have you got a thread for your carb issues? Do a sound recording of the noise and I'll see if I know what it is.

Jack, just came across the following in one of your Scooterotica posts:

"btw, Mine has a JL RZ rhs on too and have no plans to change it, ever!"

Jokes aside, I was using the thread to give me some more pointers for my MHR build. All good stuff.

Had to go and check, that post was 2014 Exhaust wasn't new then but had been on maybe a year at that point. Different crank, cylinder, head, flywheel now. With the old 210 it was great but on the MHR its out the game before the full rpm. Could be losing as much as 5bhp from the top.
All the new pipes I want are going to be months away. Out of stock or made to order. The old RZ will need a patch up to get through the Summer.

108 wrote:

Thanks for posting this!

Just want to double check, which carb did you use?

And a question after watching the video, when you roll off the throttle it seems to be smooth, the noise.

Iím getting a lot of machine gun noise when I come off the throttle, any ideas why?

Carb is Race polished Dellorto VHSH30CS. Although this one punches above its weight, it is a little small and all it's expensive parts are getting worn out. A whole new one would make more sense.

Have you got a thread for your carb issues? Do a sound recording of the noise and I'll see if I know what it is.

Done some more dremel work on the MHR about a week ago. Gave it another 1 degree of blowdown. now it's all jetted, it's going great. Better as soon as I Rode off. Goes to 9000 rpm comfortably. Rest of the scooter is suffering. Exhaust crack is now big. Can still ride it but new one is really urgent. Still a month away though.
The new CR 80 plates have started slipping at high rpm in 4TH. Back shock feels bouncy. Another $50 order to SIP is needed. I think this revision is finally it though. The way the power comes on through the gears is like a bike. And top speed now ridiculous.

Port timing is now 129 190 30.5 but my 15 year old design JL RZ is working beyond its rev range. Good for me as this means the new exhaust will improve performance even further. All the new pipes and boxes have much stronger diffuser sections and bigger volume expansion. Meaning they have way more effect when matched to the port timing. Looking forward to seeing that.

I'm going to need a bigger carb in the end. I have a VHSB38 available but will need to convert to reed to use it. Don't like reeds but going to be no choice.

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